The cosmetic industry has long sought a low-cost application device which can apply a premeasured amount of cosmetic, particularly lipstick, to an epidermal surface in a single application. Such an application device should permit the cosmetic to be easily applied, and, preferably, by a simple, single placement or impression. Apart from conventional tubes and their pencil-shaped derivatives, individual lipstick application devices are currently used chiefly to sample lipstick and require an indirect means for placement of the lip cosmetic on the lips. Independent of the application, the lip cosmetic should have the same characteristics and the same texture and feel after application as when applied using a conventional tube of lipstick of the same formulation. It is for this reason, individual lipstick application devices are, at present, limited commercially and, in general, to the use of miniaturized tubes or brush application devices, notwithstanding a plethora of current literature covering a multitude of different types of applicators for applying lip cosmetic.
Not only must the lip cosmetic be easily applied to the lips, ideally it should also be long-lasting. Currently, lipsticks are classified as being relatively easy to apply, i.e., possess a creamy consistency, or are relatively hard to apply. The relatively easy to apply lipsticks tend to come off the lips very easily when drinking, eating, or smoking, while the harder to apply lipsticks are more durable and tend to be long-lasting. Accordingly, to the lipstick user, a trade-off is required between the desirability of using an easy-to-apply lipstick having a creamy consistency, and using the more durable long-lasting lipsticks which are difficult to apply. At present, this choice is common to all lipsticks, independent of formulation.
It should be understood that a cosmetic lipstick formulation is a complex composition having a solid, waxy base containing dissolved and suspended colorants, as well as preservatives, fragrances, or flavors. All lipsticks are sold commercially in crystalline form. During crystallization, the oils are entrapped in a honeycomb-like formation, common to the micelle structure formed by the wax component. The composition of the lip formulation may be modified to adjust its consistency and its ease of application, primarily by the selection of the wax component and its concentration. The harder, "longer-wearing lipsticks" contain harder waxes and less oils, which make them difficult to apply.